GB1184670A - Fluid Flow Classifier. - Google Patents

Abstract

1,184,670. Centrifugal classifiers. ALPINE A.G. 25 Sept., 1967, No. 43602/67. Heading B2P. A fluid flow classifier for separating material according to size comprises a stationary classifying chamber having a peripheral wall 15 extending substantially continuously around a classifying rotor 2 between the side walls of which classifying fluid 11, e.g. air or water, flows radially inwardly. The fluid enters the classifier housing through a channel 28, flows through openings 12, 34 in both sides of the classifying chamber, is accelerated to the peripheral velocity of the classifying rotor 2 by radial blades 13 on the rotor and flows through annular gaps 14 between the side walls of the rotor and the chamber wall 15. The material to be classified is fed through a channel 10, enters the classifying chamber through an opening 29, is accelerated by the vanes 13 and enters through one of the gaps 14 into the space 18 between the wall 15 and the rotor 2. In the space 18 the material is whirled up and separated by the entering classifying fluid air so that the coarse particles 27 are carried around towards an exit slot 22 in the chamber wall 15 and discharged through a duct 23 to which a pneumatic suction device may be connected to assist discharge. The fine particles 21 pass with classifying fluid through the rotor to be discharged through a central discharge duct 4. A branch 24 of the classifying air stream flows through the gap 25 between the rotor 2 and the duct 4 to prevent material entering the gap when the classifier is being shut down. A flared ring 26 is mounted on a side wall of the rotor to prevent unseparated material from the upper part of the classifying chamber from falling into the annular gap 25. By narrowing the exit slot 22 the coarse particles may, as a whole or partially be made to recirculate several times so as to improve separation. The interior of the rotor may be provided with radially extending zigzag shaped channels between its side walls. In a modification, the material to be classified is fed through an opening in the peripheral wall 15 of the chamber in a direction radially of the rotor and the coarse particles are discharged in an axial direction by a worm conveyor.